Office appliance

ABSTRACT

An office appliance includes a cabinet provided with horizontally displaceable components each operable upon displacement to activate a file interlock operable to regulate the number of components which may be withdrawn at any one time. A receding door assembly is disposed above each component and manually displaceable from a vertical position enclosing its respective component to a housed position horizontally disposed within the confines of the cabinet.

United States Patent 1 1 1111 3,909,090

Breckner et al. 1 Sept. 30, 1975 OFFICE APPLIANCE 2.886.392 5/1959 Stegmaier 312/217 3337281 9/1967 Walhout 312 217 [751 Inventors: Gerald Breckne" McDonald; Leo 3,622,216 11 1971 Haunost 312/222 Terlecki, Youngstown; Gabriel Goulish, Youngstown; James Costello. Youngstown a of Ohio Prumuy E.\an1u1e/C:asm1r A. Nunberg Attorney, Agent, or Flrm Emory L. Groff, Jr. [73] Assignec: GF Business Equipment, Inc.,

Youngstown, Ohio [57] ABSTRACT [22] Filed: Nov. 18, 1974 An office appliance includes a cabinet provided with PP N05 525,016 horizontally displaceable components each operable upon displacement to activate a tile interlock Operable 52 U5. c1 312/217; 312/222 to regulate the number of ComPonents which may be [51] Int. Cl. E05C 15/04 withdrawn at any one tirm- A receding door assembly 58 Field of Search 312/216, 222 is disposed above each component manually placeable from a vertical position enclosing its respec- [56] References Cited tive component to a housed position horizontally dis- UNITED STATES PATENTS posed within the confines of the cabinet.

1,193,955 8/1916 Watson 312/217 10 Claims, 9 Drawing Figures US. Patent Sept. 30,1975 Shget 1 of 3 3,909,090

U.S. Patent Sept. 30,1975 Sheet 2 of3 3,909,09C

US. Patent Sept. 30,1975 Sheet 3 of3 3,909,090

OFFICE APPLIANCE This invention relates generally tooffice appliances and more particularly to an improved storage or file apparatus containing a plurality of stacked displaceable drawer-like components and wherein means are provided for precluding the displacement of more than one component at a time within any one cabinet. Associated with each drawer component is a separate operated receding door of improved construction.

The objectives of a file interlock system are well known to those skilled in theart to which the present invention pertains. In any storage device containing a plurality of vertically stacked storage or support elements such as drawers or shelves adapted to be selectively rectilinearly displaced to gain access thereto, an inherent hazard is the likelihood of tipping over the storage cabinet or housing when more than one heavily loaded drawer or shelf is withdrawn at any one time. Thus, the advantage of providing an interlock arrangement for precluding the operation of more than one displaceable element at a time will be readily apparent.

The present invention is especially directed to the type of office appliance commonly referred to as a lateral file, and which has recently gained noticeable popularity. In this type of device shelves and/or file drawers having no full-height front panels are provided within a cabinet and suitably mounted for rectilinear displacement therefrom to permit operator access from the side thereof when withdrawn from the cabinet. In some installations the appliance is of the open front type, that is, there is no separate enclosure means for sealing off the front of the apparatus when the displaceable drawers are in the retracted or housed condition. However, the present arrangement proposes a separate door for enclosing each drawer or shelf, which door may be manually moved from a vertical enclosing position to a horizontal position fully disposed within the confines of the cabinet over its respective drawer or shelf.

The present invention provides in an office appliance an upright cabinet or enclosure provided with a plurality of vertically stacked displaceable components which may comprise alternately disposeddrawers and writing/machine shelves each associated with a manually operable receding door displaceable from an overlying position enclosing the front of a respective one of the drawers or shelves to a fully enclosed position disposed above its respective displaceable component within the confines of the cabinet. To gain access to any one of the housed components the respective door is initially pivotally displaced to a horizontal position and subsequently rectilinearly moved into the confines of the cabinet. The then exposed shelf 'or drawer may be subsequently withdrawn from the enclosure and it is during this latter motion that the interlock system of the present invention is actuated. In the case of the drawers, the withdrawal of any one drawer actuates an interlock structure which precludes the subsequent operation of any other drawer within the cabinet as well as any writing/machine shelf disposed above the level of the displaced drawers. In the case of the withdrawal of any one of the shelves from the cabinet the interlock system is actuated in a manner serving to prevent the withdrawal of any drawer or other shelf disposed above the level of the withdrawn shelf.

The present improved file interlock system includes a plurality of vertically aligned lockbars, all of which are freely mounted within the interior of the office appliance cabinet for limited vertical displacement. A separate lockbar disposed adjacent each displaceable file component'carries a rotary cam member which is arcuately displaced by means of an activator or projecting means carried by each file component or its suspension and which serves to rotate the cam member during rectilinear displacement of the file components in order to vertically displace the respective adjacent lockbar and all other adjacent lockbars thereabove whereby locking means are placed in the path of each of the remaining activators at least above that component which is withdrawn in order to preclude subsequent withdrawal and thus opening of at least those file components located above the withdrawn file component.

Accordingly, one of the primary objects of the present invention is to provide an improved office appliance including a cabinet containing a plurality of stacked horizontally displaceable file components including alternately disposed drawers and shelves and wherein interlock means are provided to regulate the number of components which may be withdrawn from the cabinet at any one time.

Another object of the present invention is to provide an improved office appliance including a cabinet containing a plurality of vertically stacked withdrawable components, each associated with an interlock system limiting the number of said components which may be withdrawn at any one time and further provided with a displaceable door for each of the components moveable from an enclosing position overlying the front of each component when disposed within the cabinet to a receded position horizontally disposed above its respective component fully within the confines of the cabinet.

A further object of the present invention is to provide an improved office appliance including a cabinet containing a plurality of vertically stacked writing/machine shelves, each mounted for rectilinear displacement to andfrom the confines of the cabinet and provided with activating means serving to regulate an interlock system to limit the number of shelves which may be withdrawn from the cabinet at any one time.

Still another object of the present invention is to provide an improved office appliance including a cabinet containing a plurality of vertically stacked withdrawable file components, each having associated therewith a displaceable door assembly including a door panel pivotally carried by a follower assembly mounted for rectilinear movement above the displaceable file component to permit, when pivotally displaced to a horizontal position, receding movement of the door panel to a housed position fully within the confines of the cabinet.

With these and other objects in view which will more readily appear as the nature of the invention is better understood, the present invention consists of the construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A practical and preferred embodiment of the present invention is shown in the accompanying drawings, in

which:

FIG. 1 is a fragmentary side elevation, partly in section, of an office appliance according to the present invention and illustrates one of the displaceable file components in the fully extended position and two others in the fully retracted position.

FIG. 2 is a fragmentary horizontal sectional view taken along the line 22 of FIG. 1 and illustrates the door assembly as it appears when in the enclosing position.

FIG. 3 is a vertical sectional view taken along the line 33 of FIG. 2 and illustrates, the door follower assembly and its supporting cabinet channel.

FIG. 4 is a vertical sectional view similar to FIG. 3 but illustrating the receding door in its fully retracted position within the confines of the cabinet.

FIG. 5 is a fragmentary transverse sectional view taken along the line 55 of FIG. 4.

FIG. 6 is a fragmentary horizontal sectional view taken along the line 66 of FIG. 1, and illustrates one of the writing/machine shelves in the fully enclosed position within the cabinet.

FIG. 7 is fragmentary vertical sectional view taken along the line 77 of FIG. 6.

FIG. 8 is a side elevation of the rotary cam member of the tile interlock and diagrammatically illustrates its alternate positions when actuated upon displacement of one of the writing/machine shelves.

FIG. 9 is a fragmentary plan view, partly in section, and illustrates the machine/writing shelf of FIG. 6 as it appears when in the fully extended position.

Similar reference characters designate corresponding parts throughout the several figures of the drawings.

Referring now to the drawings, particularly FIG. 1, the present invention will be seen to relate to an office appliance, generally designated 1, and including a cabinet or enclosure 2 housing a plurality of vertically stacked, rectilinearly displaceable components such as the writing/machine shelves 3 and drawer 4, each of which components is adapted to be enclosed, when in the retracted position, by means of a receding door assembly 5 mounted for compound motion above each respective displaceable component. Included within the cabinet 2 is a unique interlock assembly, generally designated 6, cooperating with the displaceable components 3 and 4 to regulate the number of said components which may be withdrawn from the retracted to the extended position at any one time. It will be understood that the number and exact relative positioning of the shelves 3 and drawers 4 as contained in any one cabinet 2 is entirely flexible and is determined by the height of the cabinet 2 and desires of the customer, there being illustrated in FIG. 1 one drawer 4 and two shelves 3, which is entirely adequate for describing the construction and operation of the instand invention.

The cabinet 2 includes a pair of side walls 7-7 joined by means of a rear wall 8, a bottom wall 9 and a top wall (not shown). The side walls 77 serve to support suspension channels for guiding and retaining each of the displaceable components 3 and 4 as well as the plurality of door assemblies 5.

The construction of the door assemblies 5 will be initially described, with additional reference being made to FIGS. 24 of the drawings. Each receding door assembly 5 includes a door panel, generally designated 10, comprising an outer face 11 spaced from a rear face 12 and respectively bounded by a top edge 13, side edges 14--14 and a bottom edge 15. When in the closed position of FIG. 1 the door panel seals off the front of a cavity 16' within the confines of the cabinet 2, which cavity is intended to contain either a writing- /machine shelf assembly 3 or a drawer assembly 4 as will be described hereinafter. Means are contained within the cabinet 2 for supporting the door panel 10 in the vertical position as shown in FIG. 1 and for permitting displacement of the door panel to a horizontal position prior to manually displacing the entire door assembly 5 into a receded position within the confines of the cabinet 2 and above the top limits of its respective cavity 16' therebeneath. This support and guide means is shown most clearly in FIGS. 2-4 of the drawings and will be seen to include a follower assembly, generally designated 16, capable of being displaced from a forward-most position as shown in full lines in FIG. 2 to a rearward-most position as shown in broken lines in FIG. 2. The follower assembly structure as shown in this figure will be understood to be duplicated adjacent the opposite side wall 7 (not shown) of the cabinet 2 and includes at each side thereof a side support plate 17 comprising a longitudinal member having an outer edge 18 disposed within the confines of a door cabinet channel generally designated 19 which is rigidly affixed to the interior of the cabinet side wall 7.

The door channel 19 includes a side wall 20 juxtaposed the interior cabinet side wall and from which inwardly extends a top flange 21 and bottom flange 22 defining therebetween a guideway 23 within which the outer edge 18 of the follower assembly side support plate 17 freely travels. Vertical and lateral support for the follower assembly is provided within the door cabinet channels 19 by means of a pair of rollers 24-24 carried by each side support plate 17 adjacent the two ends thereof. These rollers 24 are preferably of a low friction composition such as nylon plastic and are carried by the side support plate 17 so that the periphery thereof projects at all times outwardly from the outer edge 18 thereof as shown most clearly in FIG. 2 of the drawings. Attachment of the rollers to the follower assembly is most readily achieved by utilizing a pin element 26, also of low friction composition, and serving as a pivot for the rollers. This pin element 26 includes a shank 27 passing through the center of each roller 24 and which is inserted within a notch 28 adjacent each end of each support plate 17. The bottom of each pin element 26 is formed with an enlarged head serving as a glide 29 adapted to be supported upon the bottom flange 22 of the door cabinet channel 19, while the top of the pin element 26 may be a rounded head 30 nor mally disposed immediately below the lower surface of the door cabinet channel top flange 21. With the foregoing structure in mind, it will be seen that the periphery of the two rollers 24 carried by side support plate 17 are constantly engaging the side wall 20 of the door cabinet channel 19 to provide lateral guiding of the follower assembly 16 while the weight of the entire receding door assembly 5 is carried by the two glides 29 projecting beneath the side support plate 17 and resting upon the upper surface of the door cabinet channel bottom flange 22.

Joining each of the above described pair of side support plates 17 associated with each receding door assembly 5 is a cross channel 31, the ends 3232 of which terminate just short of the inner edge 33 of each pair of spaced apart side support plates 17.

Connecting each end 32 of the cross channel 31 to its respective side support plate 17 is a mounting tab 34, one end of which is removably secured to the cross channel by means of an adjustable releasable fastener 35. The other end of the mounting tab 34 extends beneath the inner edge 33 of the side support plate 17 and fixably supports a shoulder pin 36 as shown in FIGS. 2 and 5 of the drawings. The distal portion of the mounting tab 34 will be seen to terminate short of the vertically offset portion 37 of the side support plate 17 The shank 38 of the shoulder pin 36 is freely disposed through a motion take-up slot 39 extending substantially the length of the side support plate 17 and includes an upper head 40 having a lateral dimension greater than that of the slot 39 such that its under surface at all times is supported on the top of the side support plate 17.

The cross channel 31 which ties together the two side support plates 1717 also serves as a support for the cross channel hinge leaf 41 engaged by a hinge pin 42 within the door panel 10. Cooperating with the hinge pin 42 is the door panel hinge leaf 43 attached to the door panel 10. When the door is in the closed position of FIGS. 1, 2 and 3 it will be observed that the entire weight of the door panel is carried by the hinge pin 42 as it remains suspended in a vertical position from this hinge pin. The forward-most portion of the door cabinet channel 19 may be provided with a door panel bumper 44 projecting forwardly therefrom and positioned so as to engage the rear face 12 of the door panel 10 when suspended in the closed or vertical position.

The operation of the receding door assembly 5 may now be described with reference to the foregoing related components. To gain access to the respective displaceable file components 3 or 4 disposed within any one cavity 16' within the cabinet 2, the operator initially must operate the receding door assembly 5 by grasping the door panel 10 and pivoting it clockwise as viewed in the drawing so as to pivot the door panel approximately 90 from its closed vertical position to a horizontal position parallel to the door cabinet channels l9l9. When the door panel is thus disposed, the simple action of pressing rearwardly upon the bottom edge area of the door panel causes the follower assembly to move from the full line position of FIG. 2 to the broken line position therein, with the door panel 10 becoming fully receded within the confines of the cabinet 2 in a horizontal plane parallel to and immediately above the plane of the door cabinet channels l9l9. During this rearward displacement of the follower assembly 16 and door panel 10 simultaneous displacement occurs between the cross channel 31 and the two side support plates 17. This action will be apparent upon a review of FIG. 2 of the drawings wherein it will be observed that in the left hand portion of this figure the shoulder pin 36 as carried by the cross channel mounting tab 34 is disposed adjacent the forward extremity of the motion take-up slot 39 while in the right hand portion of this figure the cross channel and head shoulder pin are disposed at the opposite or rear extremity of the slot 39. This relative displacement between the cross channel and side support plates may truly occur simultaneously, or on the other heand, at different periods of time during the horizontal displacement of the follower assembly 16. In other words, it will be appreciated that the shoulder pins 36 may traverse the length of the slot during the very initial rearward displacement of the door panel or alternatively, at the very end of the rearward displacement of the door panel, depending upon the relative coefficient of friction offered by the shoulder pin 36 and rollers 24 together with their respective engaging structure. In any case, the important feature is that the overall length or depth of the entire receding door assembly is significantly reduced when the door is in the fully receded position of FIG. 4 of the drawings, thereby taking full advantage of the available depth of the cabinet 2 in order to provide a door panel 10 of maximum height and accordingly a respective cavity 16 of maximum height.

The rearward-most displacement of the retracted door assembly is regulated by means of a suitable instop bumper 45 attached to the door cabinet channels 19-19 within the guide ways 23 thereof so that the rearmost roller 24 of each side support plate 17 will abut the stop bumpers 45 when the door panel is in the full receded position of FIG. 4. In order to preclude marring the finish of the door panel and also to ensure the quietest possible operation of the door assembly 5, additional nylon glide elements in the form of a bottom plate 46 and side plate 47 may be mounted atop the door cabinet channel top flanges 21 and cabinet side walls 7 respectively, adjacent the forward-most end of each cabinet channel as shown in FIG. 4 of the drawings. Additionally, an outstop bumper 48 is mounted within the confines of the door cabinet channel guideway 23 adjacent the forwardmost limit thereof in order to serve as a silent stop for each follower 16 when in its forwardmost position as when the door panel 10 is closed.

With the receding door assembly 5 now having been described, the associated movable file/support components as contained within the cavities 16' behind and- /or beneath each receding door assembly will now be discussed. The writing/machine shelf, generally designated 3, includes a bottom wall 50 bounded by a pair of side walls 51-51 all of which are substantially as deep as the depth of the interior of the cabinet 2 and which are further enclosed by a front wall 52 and rear wall 53. A suitable supporting or writing surface 54 overlies the bottom wall 50 in a spaced apart manner. Support and guiding means enabling full extension of the shelf assembly 3.is provided and includes a shelf channel 55 attached to side wall 51 and a shelf cabinet channel 56 affixed to the side wall 7 of the cabinet 2. An intermediate channel 57 engages both the shelf channel 55 andjcabinet channel 56 to form a well known type of slide'siispension assembly generally designated 58. Quite obviously, the foregoing described slide suspension assembly 58 will be utilized on both sides of the shelf assembly 3.

The rear wall 53 of the shelf assembly preferably extends vertically'no less than the height of the shelf channel 55 and serves to support a shelf hinge leaf 59 engaging the hinge pin 60. Likewise pivoting about the hinge pins 60 is a lever hinge leaf 61. Carried by the lever hinge leaf 61 is an activator or lever generally designated 62 including an inclined plate 63 terminating along its top edge in a downwardly extending stop flange 64, while the other edge of the lever terminates in a limit flange 65 extending below the hinge pin 60. The hinge assembly is suitably spring-loaded (not shown) to normally bias the lever 62 in the position as illustrated in FIG. 1 of the drawings where it will be seen that the lever limit flange 65 abuts the inner or front surface of the shelf rear wall 53 with the inclined plate 63 urged to an elevated position substantially in a plane 45 from the horizontal. The writing/machine shelf assembly 3 as shown in this figure is disposed in the fully extended position wherein it will be seen that the entire surface 54 thereof is disposed outside the confines of the cabinet 2 and thus fully accessible to an operator from three sides thereof. This outwardmost limit of the shelf may be regulated by well known means associated with the slide suspension assembly 58 and an important feature to note at this point is that when in this fully extended position the stop flange 64 of the lever 62 is disposed forward of or outside the forward periphery of a bushing 66 projecting inwardly from the sidewall 7 of the cabinet 2 and in a plane which is disposed well below the topmost limit of the lever inclined plate 63 such that subsequent efforts to retract the shelf assembly within the cabinet 2 will be fruitless since the vertically disposed stop flange 64 will immediately abut the periphery of the inwardly projecting bushings 66 to preclude any retraction of the shelf assembly 3. This stop action will be apparent since the lever assembly 62 cannot pivot any further in a counter-clockwise direction about the hinge pin 60 due to the abutment of its lever limit flange 65 against the forward surface of the shelf rear wall 53. It therefor becomes necessary to vertically displace the inclined plate 63 of the lever 62 in a downward direction about the hinge pin 60 against its associated spring force at least a sufficient distance to clear the uppermost limit of the inclined plate 63 beneath the periphery of the inwardly projecting bushings 66. This action is readily accomplished by the mere application of a slight downward force by the operators hand upon any portion of the lever 62 which extends transversely substantially the entire width of the cavity 16' and need only be applied but for an instant as the shelf assembly 3 is urged rearwardly into the confines of the cabinet, after which the hand pressure may be released when the inclined plate 63 has been moved behind the bushings 66 so that continued rearward pressure upon any portion of the shelf will move the entire shelf assembly fully within the confines of the cabinet 2.

The interaction between the writing/machine shelf assembly 3 and interlock assembly 6 may now be discussed. The interlock assembly 6 comprises a plurality of vertical lockbars 67 mounted for vertical displacement within the sidewall 7 with each lockbar associated with one of the cavities 16' and having an uppermost inwardly directed flange tip 68 at one end and a bottom offset tip 69 at the other end. With the exception of the lowermost lockbar 67 in any one cabinet 2 the offset tips 69 are disposed behind the flange tip 68 of the next lower vertical lockbar 67 such that a limit vertical displacement of all of the lockbars 67 may occur freely without any interference when a first component 3 or 4 is withdrawn from the cabinet.

Attached to each lockbar 67 adjacent the lower portion thereof is a rotary cam member, generally desig nated 70, having a central annular projection 71 extending into the cavity 16 at least to a point substan- I tially overlying the respective slide supension assembly disposed therebeneath. Suitable mounting means (not shown) are included for attaching each rotary cam member 70 to its respective vertical lockbar 67 to permit free rotary displacement thereof within the limits about to be described. Projecting from each annular projection 71, in a plane juxtaposed the inner surface of the respective lockbar 67, is a radial cam flange 72 comprising a greater cam flange 73 describing an are of substantially greater than 180 and a lesser cam flange 74 which will be seen to have a significantly lesser radius than the flange 73 and which joins the two ends of the cam flange 73. A fixed limit pin 75 carried by each vertical lockbar 67 projects inwardly to engage an arcuate slot 76 formed in the rotary cam member 70 and extending to describe an arc of approximately such that the arcuate displacement of the rotary cam member is limited to the two extremes as shown in the upper and central portions of FIG. 1 of the drawings.

Before proceeding with a description of the actuation of the interlock assembly 6 upon recilinear displacement of the shelf assembly 3 it should be observed that the end of the activator lever inclined plate 63 adjacent the interlock assembly 6 longitudinally extends beyond the confines of the shelf side walls 5l-l5 to provide a tab 77 terminating just short of the cabinet side wall 7.

With the foregoing structure in mind the operation of the interlock assembly 6 upon displacement of the shelf assembly 3 may now be readily understood, with reference to the lowermost shelf assembly 3 as shown in FIG. 1 of the drawings. Following opening of the door panel 10 and its displacement to the previously described receded position, the retracted writing/machine shelf assembly 3 is manually withdrawn from its full confinement within the cabinet 2 merely by pulling outwardly until the shelf assembly is in the position as shown in the upper portion of FIG. 1. Shortly after the initial outward displacement of the shelf assembly it will be observed that the upstanding activator lever 62;

which normally lies within the place of at least the lower portion of the rotary cam member annular projection 71 will strike the periphery of this projection 71. More particularly, the lever inclined plate tab 77 engages the lower portion of the periphery of the annu lar projection 71. The components will then appear as in FIG. 7 of the drawings and it will be seen that a friction band '78 projects from the periphery of the projection 71 to enhance the contact between the cam member and theactivator lever 62 so that continued withdrawal of the shelf assembly 3 concurrently rotates the rotary cam member 70 in a clockwise direction while elevating the entire rotary cam member 70 and its attached vertical lock bar 67 until the cam member appears in the position of the uppermost cam member illustrated in FIG. 1 of the drawings. In this elevated position the cam member is retained as the greater cam flange 73 is disposed upon the top of the flange tip 68 of the next lower vertical lockbar 67. By properly selecting the positioning of each rotary cam member 70 upon its respective vertical lockbar 67 and the radius of the greater cam flange 73, it will be seen that it is possible to ensure that when a rotary cam member 70 is displaced into its elevated position that the lowermost point of the periphery of its respective annular projection 71 will come to rest at a point disposed slightly below the uppermost tip of the inclined plate 63 of the activator lever 62 when in its normal upright position for reasons which will become apparent immediately hereinafter.

An important point to realize is that, each vertical lockbar 67 is provided with a pin stop 78 projecting inwardly into each cavity 16. The vertical positioning of each of these pin stops 78 is selected so that when the respective vertical lockbars 67 are in their normal or lowered position, that is, when the associated rotary cam member is positioned with its lesser cam flange 74 resting upon the next lower lockbar flange tip 68, no writing/machine shelves 3 above the level of any elevated lockbar 67 may be withdrawn from'the cabinet 2. To achieve the referenced interaction a stop plate 79 is mounted upon the bottom wall 50 of each shelf assembly 3 adjacent the rear wall 53 thereof. This stop plate 79 includes a vertically disposed forward edge 80 which extends downwardly a sufficient distance to strike the rear surface of the pin stop 78 carried by an adjacent vertical lockbar 67 should this respective lockbar and its pin stop be in the elevated position due to the prior withdrawal of any shelf assembly or drawer 4 therebeneath. The stop plate 79 is provided with a plurality of notches 81 each likewise provided with a vertical forward edge more closely adjacent the vertical plane passing through the activator level 62. These notches 81 serve as stop means likewise engageable by a pin stop 78 should an operator attempt to simultaneously withdraw one writing shelf 3 together with either another writing shelf 3 or drawer 4.

When it is desired to retract any writing shelf assmebly 3 from the fully extended position to the fully retracted position, the extended position lock as previously described must be initially actuated by manually depressing the lever 62 until the inwardly projecting bushing 66 is cleared, whereafter continued rearward movement of the shelf assembly into the cabinet 2 proceeds until the uppermost portion of the lever inclinded plate 63 at its juncture with the stop flange 64 engages the friction band 78' carried by the rotary cam member annular projection 71. It will be understood that since the rotary cam member 70 is in the elevated position the activator lever 62 engages the annular projection 71 only along its lower periphery to displace same in a counter-clockwise motion sufficient to arcuately displace the greater cam flange 73 from its engagement with the flange tip 68 therebeneath, whereupon continued rearward movement of the shelf assembly permits lowering of the rotary cam member and its lockbar by gravity as it is rotated to present the lesser cam flange 74 at the bottom most position and resting upon the flange tip 68 of the next lower lockbar 67. The operator continues to move the shelf assembly rearwardly to the limit of its slide supension assembly, at which time the shelf assembly is fully contained within the cabinet 2 and the interlock assembly 6 will be in its normal at rest position.

The subsequent opening of any retracted writing shelf assembly 3 located below a writing shelf which is already disposed in the extended position is precluded due to the immobilizing of all rotary cam members 70 located beneath the elevated vertical lockbars 67. This immobilization is due to the fact that the plurality of vertical lockbars 67 when initially installed within the cabinet 2 are provided with only enough axial clearance within the cabinet to permit the vertical displacement as caused by the arcuate displacement of but one rotary cam member greater cam flange 73. ln other words, reviewing FIG. 1 of the drawings, it will be seen that the uppermost rotary cam member 70 has already been vertically displaced and arcuately rotated. Therefore, a subsequent attempt to extend the lower writing shelf assembly 3 from within the cabinet will cause the activator lever inclined plate 63 thereof to strike the periphery of the lowermost rotary cam member annular projection 71 and this in itself serves as a stop since the vertical lockbar 67 carried by this lowermost rotary cam member is precluded from any vertical displacement dueto the prior vertical displacement caused by rotation of the uppermost rotary cam member 70.

if a drawer 4 is placed within a cavity 16' instead of a'writing/machine shelf 3 the activator means for regulating the interlock assembly 6 may comprise a saddle, generally designated 82, mounted atop the drawer suspension channel 83 and containing an inclined front ramp 84 and rear ramp for respectively engaging and displacing the adjacent rotary cam member annular projection 71 during extension and retraction of the associated drawer 4, thereby actuating the interlock assembly 6 in a manner analogous to the activator lever 62 of the shelf assembly 3. The saddle 82 is rigid and thus no pin stop plate 79 is required in the case of the drawers 4. This follows since an attempt to open a drawer 4 above an already extended component 3 or 4 will be precluded as the saddle 82 abuts the elevated flange tip 68 and when attempting to open a drawer 4 disposed beneath and extended component 3 or 4, the rigid saddle front ramp 84 will strike the immobile cam member projection 71.

We claim:

1. An office appliance including, a cabinet having a pair of spaced apart side walls, a plurality of vertically aligned horizontally displaceable file components disposed within said cabinet, means mounting said components within said cabinet and between to said side walls for rectilinear movement from a retracted position Within the confines of said cabinet to an extended position outside said cabinet, an interlock assembly carried by said cabinet, activating means displaceable upon movement of any one said component and engaging said interlock assembly to limit the number of said components displaceable from a retracted to an extended position at any one time, a receding door assembly disposed within said cabinet above at least one said file component, said door assembly including a follower assembly provided with mounting means for rectilinear motion substantially the depth of said cabinet,

and a door panel pivotally attached adjacent its top to said follower assembly, whereby, when said follower assembly is displaced to the forward limit of its travel said door panel may be vertically disposed to enclose said cabinet in front of a respective retracted component therebeneath and subsequently said panel may be pivotally displaced to a horizontal plane prior to retraction into said cabinet with concurrent rearward displacement of said follower assembly.

2. An office appliance including, a cabinet having a pair of spaced apart side walls, a plurality of vertically aligned horizontally displaceable file components disposed within said cabinet, means mounting said components to said side walls for rectilinear movement from a retracted position within the confines of said cabinet to an extended position outside said cabinet, an

interlock assembly carried by said cabinet, activating means displaceable upon movement of any one said component and engaging said interlock assembly to limit the number of said components displaceable from a retracted to an extended position at any one time, said'file components including shelf assemblies each having a pair of side walls and a rear wall, said mounting means comprising channel elements attached respectively to said cabinet side walls and shelf side walls, said activating means including a lever pivotally attached to said shelf rear wall, means normally urging said lever into an elevated position, said interlock assembly including a plurality of vertically stacked slidable lock bars disposed adjacent said channel elements attached to said cabinet side walls for limited total vertical displacement therein, a cam member attached to each said lockbar for rotary displacement thereon, each said cam member provided with an annular projection extending into the horizontal plane of said shelf lever for activation thereby, a flange on said cam member having adjacent portions of greater and lesser radii, said flange portions engaging the top of the next lower said lockbar to position the attached lockbar and all lockbars thereabove at alternate elevations when arcuately displaced, stop means carried by each said shelf said follower assembly mounting means includes a pair of door channels fixedly attached to said cabinet side walls, each said channel provided with top and bottom flanges and an intermediate side wall defining a guideway, a pair of side support plates each having an outer edge disposed within one of said guideways, roller means carried by each said support plate and engaging a respective said channel, a cross channel connecting said pair of support plates, hinge means joining the forward portion of said cross channel to said door panel to provide said pivotal attachment between said follower assembly and door panel, and stop means on said channels limiting the forward and rearward displacement of said follower assembly.

4. An office appliance according to claim 1 wherein, said file components include a shelf assembly having an upstanding rear wall, said activating means comprising a lever pivotally attached to said rear wall, an inclined plate on said lever normally spring-urged to an elevated position above said rear wall and engageable with said interlock assembly during withdrawal and retraction of said shelf assembly, a stop flange on said inclined plate, a projection fixedly attached to said cabinet and extending inwardly into the path of said lever plate adjacent the front of said cabinet whereby, upon displacement of said shelf assembly to its fully extended position said lever plate engages and is deflected by said projection prior to returning to its elevated position with said shelf assembly fully extended and rearward displacement of said shelf assembly is normally precluded as said lever stop flange on said elevated plate abuts said projection but may proceed upon manual de-' flcction of said plate and stop flange below the level of said projection.

5. An office appliance according to claim 1 wherein, said file components include a drawer having an open front, said mounting means comprising channel ele ments attached respectively to said cabinet side walls and said drawer, said activating means'including a saddle carried by one said drawer attached channel and engageable with said interlock assembly upon exten-' sion and retraction of said drawer to restrict the extension of other file components from said cabinet when one said drawer is extended.

6. An office appliance according to claim 2 wherein, said lever includes an inclined plate and limit flange, spring-biased hinge, means attaching said lever to said rear wall intermediate said plate and limit flange and normally biasing said plate into anelevated position with said limit flange abutting said rear wall and lock means fixedly attached to said cabinet projecting into the path of said inclined plate to preclude retraction of said shelf assembly from a fully extended position without manual deflection of said plate to bypass said lock means.

7. An office appliance according to claim 3 wherein, said roller means includes a pair of rollers on each said support plate, and a pin element having a vertical shank attaching each said roller to its respective support plate with the periphery of said rollers juxtaposed said channel side walls and vertically spaced from said channel top and bottom flanges.

8. An office appliance according to claim 3 wherein, each said support plate is provided with an elongated slot, and means carried by the ends of said cross channel slidably engaging said slots to permit relative horizontal displacement between said door panel attached to said cross channel and said support plates.

9. An office appliance according to claim 4 wherein.

said stop means on said door channels includes bumpers mounted at the forward and rearward limits of said.

guideways and engageable by said roller means.

l0. An office appliance according to claim 3 wherein, said hinge means includes a cross channel hinge leaf having a vertically offset hinge pin, a door panel hinge leaf connected with said hinge pin whereby, when said panel is pivoted about said hinge pin into a horizontal position and displaced into retracted position said panel is disposed in a plane above said door channel top flanges. 

1. An office appliance including, a cabinet having a pair of spaced apart side walls, a plurality of vertically aligned horizontally displaceable file components disposed within said cabinet, means mounting said components within said cabinet and between to said side walls for rectilinear movement from a retracted position within the confines of said cabinet to an extended position outside said cabinet, an interlock assembly carried by said cabinet, activating means displaceable upon movement of any one said component and engaging said interlock assembly to limit the number of said components displaceable from a retracted to an extended position at any one time, a receding door assembly disposed within said cabinet above at least one said file component, said door assembly including a follower assembly provided with mounting means for rectilinear motion substantially the depth of said cabinet, and a door panel pivotally attached adjacent its top to said follower assembly, whereby, when said follower assembly is displaced to the forward limit of its travel said door panel may be vertically disposed to enclose said cabinet in front of a respective retracted component therebeneath and subsequently said panel may be pivotally displaced to a horizontal plane prior to retraction into said cabinet with concurrent rearward displacement of said follower assembly.
 2. An office appliance including, a cabinet having a pair of spaced apart side walls, a plurality of vertically aligned horizontally displaceable file components disposed within said cabinet, means mounting said components to said side walls for rectilinear movement from a retracted position within the confines of said cabinet to an extended position outside said cabinet, an interlock assembly carried by said cabinet, activating means displaceable upon movement of any one said component and engaging said interlock assembly to limit the number of said components displaceable from a retracted to an extended position at any one time, said file components including shelf assemblies Each having a pair of side walls and a rear wall, said mounting means comprising channel elements attached respectively to said cabinet side walls and shelf side walls, said activating means including a lever pivotally attached to said shelf rear wall, means normally urging said lever into an elevated position, said interlock assembly including a plurality of vertically stacked slidable lock bars disposed adjacent said channel elements attached to said cabinet side walls for limited total vertical displacement therein, a cam member attached to each said lockbar for rotary displacement thereon, each said cam member provided with an annular projection extending into the horizontal plane of said shelf lever for activation thereby, a flange on said cam member having adjacent portions of greater and lesser radii, said flange portions engaging the top of the next lower said lockbar to position the attached lockbar and all lockbars thereabove at alternate elevations when arcuately displaced, stop means carried by each said shelf assembly adjacent said rear wall, and stop means extending from said lockbars and displaceable into the path of said shelf stop means when said lockbars are elevated upon arcuate displacement of one said cam member to preclude outward movement of any additional shelf assembly disposed above an extended shelf assembly.
 3. An office appliance according to claim 1 wherein, said follower assembly mounting means includes a pair of door channels fixedly attached to said cabinet side walls, each said channel provided with top and bottom flanges and an intermediate side wall defining a guideway, a pair of side support plates each having an outer edge disposed within one of said guideways, roller means carried by each said support plate and engaging a respective said channel, a cross channel connecting said pair of support plates, hinge means joining the forward portion of said cross channel to said door panel to provide said pivotal attachment between said follower assembly and door panel, and stop means on said channels limiting the forward and rearward displacement of said follower assembly.
 4. An office appliance according to claim 1 wherein, said file components include a shelf assembly having an upstanding rear wall, said activating means comprising a lever pivotally attached to said rear wall, an inclined plate on said lever normally spring-urged to an elevated position above said rear wall and engageable with said interlock assembly during withdrawal and retraction of said shelf assembly, a stop flange on said inclined plate, a projection fixedly attached to said cabinet and extending inwardly into the path of said lever plate adjacent the front of said cabinet whereby, upon displacement of said shelf assembly to its fully extended position said lever plate engages and is deflected by said projection prior to returning to its elevated position with said shelf assembly fully extended and rearward displacement of said shelf assembly is normally precluded as said lever stop flange on said elevated plate abuts said projection but may proceed upon manual deflection of said plate and stop flange below the level of said projection.
 5. An office appliance according to claim 1 wherein, said file components include a drawer having an open front, said mounting means comprising channel elements attached respectively to said cabinet side walls and said drawer, said activating means including a saddle carried by one said drawer attached channel and engageable with said interlock assembly upon extension and retraction of said drawer to restrict the extension of other file components from said cabinet when one said drawer is extended.
 6. An office appliance according to claim 2 wherein, said lever includes an inclined plate and limit flange, spring-biased hinge means attaching said lever to said rear wall intermediate said plate and limit flange and normally biasing said plate into an elevated position with said limit flange abutting said rear wall and lock means fixedLy attached to said cabinet projecting into the path of said inclined plate to preclude retraction of said shelf assembly from a fully extended position without manual deflection of said plate to bypass said lock means.
 7. An office appliance according to claim 3 wherein, said roller means includes a pair of rollers on each said support plate, and a pin element having a vertical shank attaching each said roller to its respective support plate with the periphery of said rollers juxtaposed said channel side walls and vertically spaced from said channel top and bottom flanges.
 8. An office appliance according to claim 3 wherein, each said support plate is provided with an elongated slot, and means carried by the ends of said cross channel slidably engaging said slots to permit relative horizontal displacement between said door panel attached to said cross channel and said support plates.
 9. An office appliance according to claim 4 wherein, said stop means on said door channels includes bumpers mounted at the forward and rearward limits of said guideways and engageable by said roller means.
 10. An office appliance according to claim 3 wherein, said hinge means includes a cross channel hinge leaf having a vertically offset hinge pin, a door panel hinge leaf connected with said hinge pin whereby, when said panel is pivoted about said hinge pin into a horizontal position and displaced into retracted position said panel is disposed in a plane above said door channel top flanges. 